XML 141 R83.htm IDEA: XBRL DOCUMENT v3.8.0.1
Investments - Other Than Temporary Impairment (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]      
Credit impairments $ 2 $ 21 $ 6
Impairments on equity securities and other impairments 8 27 41
Intent-to-sell impairments 0 2 30
Total impairments 8 27 41
Cumulative Credit Impairments      
Beginning balance (110) (113) (128)
Additions for credit impairments recognized on:      
Securities not previously impaired (1) (16) (4)
Securities previously impaired (1) (5) (2)
Reductions for credit impairments previously recognized on:      
Securities that matured or were sold during the period 76 15 10
Securities the Company made the decision to sell or more likely than not will be required to sell 0 0 1
Securities due to an increase in expected cash flows 11 9 10
Ending balance (25) (110) (113)
Equity securities      
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]      
Impairments on equity securities and other impairments 6 4 2
Other      
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]      
Impairments on equity securities and other impairments $ 0 $ 0 $ 3